LAUSR

Abstract We have shown that as the combined effect of alloy and temperature increases, the magnons created in the C o x P t 1 − x ∕ P t multilayers undergo a transition in nature. From a purely quantum behavior at low temperature, these magnetic excitations acquire a behavior of the classical limit of localized particles (their associated wavelength is very low) at high temperature. The magnetization per spin calculated M c a l z ( T , x ) using an extended average number of particles forming the mixture of these two types of magnons created shows, indeed, a change of slope of the tangent to its curve at a temperature T = T r ( x ) . This would reflect a spin reorientation transition (SRT) from out-of-plane to in-plane observed experimentally in this type of materials. The comparison of M c a l z ( T , x ) with the experiment is indeed very satisfactory.